Schema Types Configuration

When setting up codegen for the first time, you'll need to specify a schemaNamespace for your generated schema types along with the moduleType to use. These values comprise the output.schemaTypes property in your codegen configuration.

The moduleType property tells the code generation engine how you plan to link the generated schema types to your project. The code generation engine uses this information to ensure that it generates properly formed models and import statements.

In this section, we will consider a number of factors of your project to answer the question:

Which schema moduleType should you use?

The types in your GraphQL schema will be translated into generated Swift types that must be included in your project. The generated schema types can be included in your project by creating a separate "schema module" for them or by embedding them directly in one of your own targets.

The key difference between these approaches is how they are namespaced.

• When using a schema module, your schema types will be public top-level symbols in a module using the provided schemaNamespace as the module name.

• When embedded in a target, the schema types are enclosed in a caseless enum using the provided schemaNamespace as the enum name.

Schema module

For most projects, we recommend creating a "schema module" to contain your schema types. This enables you to share your generated models across modules as your project grows. You can use either the .swiftPackageManager or .other options to create a schema module.

With this approach your schema types will be public top-level symbols in a module using the provided schemaNamespace as the module name.

For a single target project configuration, link this package to your project target. For a multi-module project configuration, you will need to link this package to any modules that contain generated operation models or use the schema types directly.

.swiftPackageManager

The .swiftPackageManager option is the quickest and most convenient way to generate your schema types if your project uses SPM.

Using this moduleType, the code generation engine can automate the creation of a schema module as an SPM package. A Package.swift file will be generated using the provided schemaNamespace as the package name.

In addition to the generated types, you can include other Swift files in the Sources folder of the generated SPM package and they will automatically be included in the schema module.

.other

The .other option allows you to generate schema types to be included in a module you define yourself. This can be used with any package manager or build system that your project is using. You can also include these files in a manually created Xcode target for your module.

Embed schema types in your target

You can also include schema types directly in an existing target in your project. While we still recommend using a seperate schema module for most projects, this allows the flexibility to use Apollo in advanced, custom use cases.

With this approach, the schema types are enclosed in a caseless enum using the provided schemaNamespace as the enum name. This functions as a namespace to prevent any possible naming conflicts between generated types and other types within the target they are embedded in.

For a multi-module project configuration, you will need to link the target containing the embedded schema types to any modules that contain generated operation models or use the schema types directly.

.embeddedInTarget(name: String)

To embed the schema types in your own target, use .embeddedInTarget(name: String) option as the value of the output.schemaTypes.moduleType property.